Drive-in tool with improved safety device

PRIORITY CLAIM

0001This patent application is a national stage entry of PCT Application No. PCT/US2016/030385, which was filed on May 2, 2016, which claims priority to and the benefit of European Patent Application No. 15166582.5, which was filed on May 6, 2015, the entire contents of which are incorporated herein by reference.

0002The present disclosure relates to a drive-in tool for driving fasteners into a workpiece by way of drive-in cycles where a safety device is to prevent unintentional tripping after a predetermined time when the trigger is actuated.

0003A generic drive-in tool is shown in DE 10 2013 106 657 A1 which is a valuable contribution to the prior art. In the case of said drive-in tool, a safety device, designated there as a resetting arrangement, is activated by a first drive cycle which is carried out in the single trip mode which is named as such in this case. The safety device transfers the tool into a secured state after a pre-determined delay time insofar as the trigger remains pressed and insofar as no drive cycle takes place within the delay time.

0004EP 2 767 365 A1 relates to a pneumatic nail driving tool which, among other things, comprises a second control valve which, when the tripper is actuated, is driven independently of an actuation of the contact sensor, a chamber which is either ventilated or vented by way of a throttle when the second control valve is actuated, and a blocking piston which is displaced from an idle position into a blocking position when the pressure in the chamber passes a pre-determined pressure threshold, and which prevents the tripping of a drive-in operation in the blocking position.

0005The inventor found the prior art to be disadvantageous insofar as to increase safety the flexibility of tool use is limited and/or a costly structural design is necessary. One object of the present disclosure was to improve the disadvantages of the prior art, in particular to increase the flexibility of tool use and at the same time to ensure comparable safety.

0006Various objects are achieved by the tool defined by the independent claims. Advantageous further developments of the tool are defined in the dependent claims.

0007In particular, one object is achieved by a drive-in tool for driving fasteners into a workpiece, wherein the tool comprises: <ul id="ul0003" list-style="none"><li id="ul0003-0001" num="0000"><ul id="ul0004" list-style="none"><li id="ul0004-0001" num="0008">an actuator unit, by way of which the fasteners are drivable into the workpiece in drive-in cycles,</li><li id="ul0004-0002" num="0009">a trip arrangement, by way of which the drive-in cycles of the actuator unit are trippable, wherein the trip arrangement comprises a trigger element which is manually operable and comprises an idle state and a pressed state, wherein the trip arrangement further comprises a workpiece contact element which is actuatable by placing the drive-in tool onto the workpiece,</li><li id="ul0004-0003" num="0010">a gas pressure source connection to which a gas pressure source is connectable,</li><li id="ul0004-0004" num="0011">a safety device which is coupled with the trigger element and is set up to bring about a transfer of the drive-in tool from a trip-ready state into a secured state after expiry of a delay time which proceeds from an activation of the safety device,</li><li id="ul0004-0005" num="0012">wherein the safety device comprises a control volume,</li><li id="ul0004-0006" num="0013">wherein the safety device comprises an activation element which is changeable between a first and a second position by way of the trigger element,</li><li id="ul0004-0007" num="0014">wherein in the first position of the activation element a pneumatic connection is defined, in a preferred manner by way of the activation element, between the control volume and the gas pressure source connection, which is hereafter referred to as charging connection,</li><li id="ul0004-0008" num="0015">and wherein in the second position of the activation element a pneumatic connection is defined, in a preferred manner by way of the activation element, between the control volume and a pressure sink, which is hereafter referred to as discharging connection, and</li><li id="ul0004-0009" num="0016">wherein in a preferred manner at least one connection from the charging connection and the discharging connection comprises a smallest cross-sectional flow area which, together with a gas pressure of the gas pressure source, determines the delay time of the safety device.</li></ul></li></ul>

0017One object is further achieved in particular by a method for driving fasteners into a workpiece <ul id="ul0005" list-style="none"><li id="ul0005-0001" num="0000"><ul id="ul0006" list-style="none"><li id="ul0006-0001" num="0018">wherein the fasteners are driven by way of an actuator unit into the workpiece in drive-in cycles,</li><li id="ul0006-0002" num="0019">wherein the drive-in cycles of the actuator unit are tripped by way of a trip arrangement, wherein a trigger element of the trip arrangement is manually operated and in this case is moved from an idle state into a pressed state, wherein a workpiece contact element is actuated by placing the drive-in tool onto the workpiece,</li><li id="ul0006-0003" num="0020">wherein a gas pressure source connection is connected to a gas pressure source,</li><li id="ul0006-0004" num="0021">wherein a safety device which is coupled with the trigger element brings about a transfer of the drive-in tool from a trip-ready state into a secured state after a delay time which proceeds from an activation of the safety device, by an activation element being changed between a first and a second position by way of the trigger element,</li><li id="ul0006-0005" num="0022">wherein in the first position of the activation element a first pneumatic connection is defined in a preferred manner by way of the activation element between the control volume and the gas pressure source connection, which is hereafter referred to as charging connection,</li><li id="ul0006-0006" num="0023">and wherein in the second position of the activation element a second pneumatic connection is defined in a preferred manner by way of the activation element between the control volume of the safety device and a pressure sink, which is hereafter referred to as discharging connection,</li><li id="ul0006-0007" num="0024">wherein a maximum gas flow, which determines the delay time of the safety device, flows through in a preferred manner at least one connection from the charging connection and the discharging connection.</li></ul></li></ul>

0025In contrast to the drive-in tool mentioned in the introduction, the flexibility of the tool use is increased, as the safety device is activatable independently of the state of the workpiece contact element and consequently a first single trip mode drive-in cycle does not have to be performed first of all in order to activate the safety device for the first time. The user is able to operate the tool from the start after choosing single trip mode or contact release mode (an operating mode in which drive-in operations are able to be tripped within the delay time of the safety device by successively placing and actuating the workpiece contact element with the trigger element held pressed in each case). At the same time, comparable safety is maintained in this case as the safety device still transfers the tool into a secured state after a pre-determined delay time such that even if the user inadvertently presses the trigger before the user has tripped a first drive cycle, unintentional tripping of a drive-in cycle is only possible within the pre-determined delay time, otherwise however it is not. The tool comprises an activation element for this purpose by way of which an activation of the safety device is coupled with the trip movement by the displacement of the activation element by the trigger element when the trigger element is pressed being utilized to cause the safety device to be activated.

0026Fasteners are, for example, nails, pins or special screws that are able to be driven-in. Wood, metal or concrete can be considered as the example workpiece.

0027In a preferred manner, the actuator unit is a pneumatic actuator unit where the expenditure of force necessary for the driving-in is provided purely from pneumatic energy. In a preferred manner, the actuator unit comprises an operating piston which is guided in an operating cylinder. In a preferred manner, in this case, the actuator unit comprises a main trip valve, in a preferred manner a non-return valve, by way of which the operating cylinder is fillable abruptly with compressed air such that the drive-in piston is moved in the direction of the tool tip. In a preferred manner, the operating piston is connected to a drive-in piston which acts upon the fasteners to be driven-in. A drive-in cycle is a recurring sequence which the actuator unit carries out for consecutively driving-in fasteners.

0028In the trip-ready state, it is possible for the user to trip a drive-in cycle—in the secured state this is not possible for the user to do.

0029In a preferred manner, the control volume is an interior of the tool which is set up for the temporary storage of pneumatic energy. In a preferred manner, it is arranged directly adjoining the tool working cylinder which contains the working piston. In a preferred manner, it surrounds the lateral surface of the operating cylinder completely by 360° at least in one region. In a preferred manner, the tool comprises a ventilation arrangement (e.g., openings in the operating cylinder), by way of which the control volume is fillable with compressed air during the course of the drive-in operation.

0030The trigger element, for example, can be pivotable or linearly displaceable, e.g., a lever or knob. In a preferred manner, it is pre-stressed into the idle state by way of a spring. In a preferred manner, the trigger element is set up to activate the safety device by a change from its idle state into the pressed state (even) when the workpiece contact element is not actuated.

0031In a preferred manner, one position from the first and the second position of the activation element is an activation position for activating the safety device, i.e., a change in the activation element from the other position into the activation position allows a delay time to start to elapse before the safety device then transfers the tool into the secured state. In a preferred manner, the activation element is in the activation position when the trigger element is in the pressed state.

0032The term pneumatic connection between two locations/objects is to be understood in a preferred manner as a fluid-permeable pathway (from start to finish) or, where applicable, as the sum of all the fluid-permeable pathways which, where applicable, connects or connect the two locations/objects together such that fluid is able to flow from the one to the other location/object. In a preferred manner, the pneumatic connection produced from the charging connection and the discharging connection, which is provided by way of the activation element in the activation position, is the connection which comprises the smallest cross sectional flow area which, together with the gas pressure of the gas pressure source connection, determines the delay time. In a preferred manner, said connection is the discharging connection, i.e., by way of which air from the control volume flows to the pressure sink. In a preferred manner, the discharging connection extends through one, in a preferred manner two openings in the activation element (in a preferred manner present in a lateral surface of an activation element which is realized as a tube piece). In a preferred manner, said opening forms a smallest cross sectional flow area which, together with the gas pressure, defines the pre-determined delay time. In a preferred manner, an adjusting needle which forms a needle valve is arranged in said opening, said adjusting needle in a preferred manner being conically tapered and it consequently being possible to modify the cross sectional flow area of the opening by displacing the needle, e.g., by way of rotating an adjusting screw on which the needle is arranged. As a result of the needle, a particularly small cross sectional flow area is achieved, in a preferred manner smaller than can be achieved using a conventional drill. The charging connection and/or the discharging connection are delimited in a preferred manner by one or several of the following components, i.e., for example, the connection extends along the corresponding element and/or through an opening or groove (e.g., between two O-ring seals) of the corresponding element: activation element, housing of the trip valve (see below), standby element (see below) and trip element.

0033On account of the smallest cross section flow area, the one connection produced from the charging connection and the discharging connection comprises a high flow resistance which enables slow discharging or charging (depending on the case).

0034In a preferred manner, the safety device is set up to transfer the tool from the secured state into the trip-ready state (and in a preferred manner to keep the same stable in said state), when the tool is connected to an energy supply and the trigger element is situated in the idle state thereof. As a result, the trip-ready state of the tool is defined as a standard state such that the user finds the instrument with the trigger not pressed and the energy source connected in the trip-ready state and the trip-ready state does not only have to be achieved by a first special drive-in cycle (e.g., single tripping).

0035An activation of the safety device is to be understood in a preferred manner as an activation of a countdown, the countdown running for as long as the safety device is activated—the safety device is deactivated in a preferred manner by being reset (either by a drive-in operation or by the trigger—or in a preferred variant according to <figref idref="DRAWINGS">FIGS. 10 to 12</figref> the trigger element and the workpiece contact element—being transferred into the idle state again) or by the pre-determined time elapsing, i.e., a countdown runs in the activated state of the safety device, whilst in the deactivated state no countdown runs. In the deactivated state of the safety device the tool is able to be situated in the secured or in the trip-ready state—both are possible.

0036In a preferred manner, the safety device is resettable as a result of a drive-in cycle (the drive-in cycle is only possible as long as the safety device has not yet brought about a transfer of the tool into the secured state) or as a result of a change of the trigger element—or in a preferred variant according to <figref idref="DRAWINGS">FIGS. 10 to 12</figref>: the trigger element and the workpiece contact element—from the pressed state into its idle state. As a result, the user is able to keep the instrument in the standby state by way of each of said two actions. Consequently, for example, continuous operation is realizable in the contact cycle without the trigger having to be released and in addition the releasing of the trigger also causes the safety device to be reset, in this case the tool also being transferred into the trip-ready state insofar as the tool was situated in the secured state.

0037In a further exemplified embodiment of the present disclosure, the correspondingly other connection from the charging connection and the discharging connection comprises a larger smallest cross-sectional flow area than the one connection from the charging connection and the discharging connection. In a further method according to the present disclosure, a stronger gas flow flows through the correspondingly other pneumatic connection at the same applied pressure than in the one connection.

0038As a result, once the trigger (without bringing about a trip) has been held pressed until the safety device has transferred the tool into the secured state, the non-secured state can be assumed again quicker, i.e., within a shorter time period than the delay time, which, for example, in the case of a sufficiently large minimal cross sectional flow area of the other connection from the charging connection and the discharging connection can even be immediately perceptible. On account of the larger smallest cross sectional flow area, the other connection from the charging connection and the discharging connection comprises a low flow resistance which enables rapid discharging or charging (depending on the case).

0039In a further exemplified embodiment of the present disclosure, the smallest cross sectional flow area, which, together with the gas pressure, determines the delay time of the safety device, is arranged in precisely one of the following pneumatic connections: <ul id="ul0007" list-style="none"><li id="ul0007-0001" num="0000"><ul id="ul0008" list-style="none"><li id="ul0008-0001" num="0040">in a pneumatic connection between the activation element and the gas pressure source connection;</li><li id="ul0008-0002" num="0041">in a pneumatic connection between the activation element and the pressure sink;</li><li id="ul0008-0003" num="0042">in a pneumatic connection which exists in both the first and the second position of the activation element between the control volume and the gas pressure source connection;</li><li id="ul0008-0004" num="0043">in a pneumatic connection which exists in both the first and the second position of the activation element between the control volume and the pressure sink. In a further method according to the present disclosure, the gas flow which defines the delay time flows in a corresponding pneumatic connection.</li></ul></li></ul>

0044As a result, alternative advantageous realizations for different cross sectional flow areas of the charging connection and the discharging connection are provided since this means that a separate by-pass line with a non-return valve is not necessary. In a preferred manner, along the pneumatic path between the smallest cross sectional flow area which defines the delay time and at least one from the pressure sink and the gas pressure source connection, there is no line portion present which is utilized in common both for the charging connection and for the discharging connection.

0045In a further exemplified embodiment of the present disclosure, the tool comprises a pneumatic line which is both part of the charging connection and part of the discharging connection and which extends from the activation element toward the control volume, and wherein the tool further comprises two lines which are separate from one another, wherein one of the lines which are separate from one another is part of the charging connection and in a preferred manner is not part of the discharging connection and extends from the activation element toward the gas pressure source connection and the other of the lines which are separate from one another is part of the discharging connection and in a preferred manner is not part of the charging connection and extends from the activation element toward the pressure sink, wherein the smallest cross-sectional flow area, which, together with the gas pressure, determines the delay time of the safety device, is present in precisely one of the lines which are separate from one another.

0046As a result, a Y configuration is provided with the activation element as the node point, by way of which the different cross sectional flow areas of the discharging and charging connection are realizable in a structurally advantageous manner. As an alternative to such a Y configuration, the tool comprises in a preferred manner a bridging line and the smallest cross section flow area is situated in the common line and is bridged or connected in parallel by way of the bridging line in a position (from the first and second position) of the activation element and is not bridged or connected in parallel in the other position of the activation element such that on the whole a larger cross sectional flow area is produced in the one position than in the other position.

0047In a further exemplified embodiment of the present disclosure, the safety device is set up to transfer the tool into the secured state if a pressure threshold in the control volume is fallen below. In a further method according to the present disclosure, the tool is correspondingly transferred into the secured state.

0048As a result, the safety of the tool is further increased as a lower pressure provides a more stable state than a higher pressure and the tool, striving for the more stable state (also generally in the event of malfunctions), is consequently blocked more securely should unexpected failures occur in any components (e.g., control volume leakage).

0049In a further exemplified embodiment of the present disclosure, the charging connection is present when the trigger element (and in a preferred manner the workpiece contact element) is situated in its idle state. In a further method according to the present disclosure, the control volume is filled with compressed air when the trigger element (and in a preferred manner the workpiece contact element) is in its idle state.

0050As a result, the control volume is fillable with the trigger element released (and in a preferred manner with the workpiece contact element not actuated) such that in the trip-ready state a high air pressure is present in the control volume.

0051In a further exemplified embodiment of the present disclosure, the trip arrangement comprises a trip valve which is coupled, preferably mechanically, with the trigger element. In a further method according to the present disclosure, a trip valve is operated by way of the trigger element.

0052In a preferred manner, component parts of the trip valve are one or several of the following components: trip valve housing, activation element, trip element (see below) and standby element. In a preferred manner, the trip valve is coupled with the trigger element purely mechanically by way of solid bodies (without fluid). In a preferred manner the trip valve is accommodated in a trip valve housing which is separate to the housing of the tool and is consequently simple to replace or retrofit. In a preferred manner, the activation element, in a preferred manner also the standby element, in a preferred manner also the trip element, is accommodated in the trip valve housing. The activation element, in a preferred manner also the standby element, in a preferred manner also the trip element, is in each case in a preferred manner part of the trip valve. The trip valve housing is sleeve-shaped in a preferred manner with a front region which faces the trigger element and a rear region which is remote from the trigger element. On the front side it comprises in a preferred manner an open end face and on the rear side a substantially closed end face. In a preferred manner, the tool comprises a venting line for the preferred permanent connection of a volume which is (also) defined by the rear region of the trip valve housing, e.g., this is a line provided in the tool housing, in a particularly preferred manner, however, a line which is defined by the trip valve (and is consequently simple to retrofit) and which in a preferred manner extends from the rear region toward the front region, e.g., an axial channel in the trip element (see below) or an axial channel or a preferred outer axial groove in the trip valve housing. As a result of venting the said volume, the accuracy of the valve is increased in particular as then no disadvantageous pressure fluctuations are formed there just as a result of the movements of the trip valve components in the trip valve housing.

0053In a further exemplified embodiment of the present disclosure, the control volume is realized by way of the trip valve.

0054This provides a compact design of the safety device which is also easily retro-fittable by way of replacing a conventional trip valve by a trip valve according to the present disclosure. An existing tool housing can consequently continue to be utilized and it is not necessary to modify the tool housing (to a large extent or at all) in order to provide the control volume. The term realize is to be understood in a preferred manner as a housing and/or one or several component parts of the trip valve defining a space which is controllable in a fluid-technical manner per discharging connection and charging connection. This does not exclude existing spaces in the tool housing being able to define parts of the control volume. In a preferred manner, in this case, however, more than 50%, in a preferred manner 75% and in a quite preferred manner 90% of the control volume is realized by the trip valve or only tool housing regions which are directly adjacent the trip valve defines the control volume. In a particularly preferred manner, the control volume is completely integrated into the trip valve. It is particularly preferred in this case when an adjusting needle is arranged as mentioned beforehand in the opening or the cross section which determines the delay time of the safety device, as then the control volume can be designed to be very small and space-saving. Surprisingly, it has additionally been ascertained that, although a reduction in the control volume makes greater demands on the accuracy of the smallest cross sectional flow for defining the delay time, said reduction also provides the advantage of resetting the control volume in an even faster manner, as even less air has to be replaced in order to influence the pressure in the control volume.

0055In a further exemplified embodiment of the present disclosure, when the tool is in the trip-ready state and the trigger element is in the pressed state and at the same time the workpiece contact element is actuated, the trip valve defines a pneumatic connection which <ul id="ul0009" list-style="none"><li id="ul0009-0001" num="0000"><ul id="ul0010" list-style="none"><li id="ul0010-0001" num="0056">is the discharging connection or another discharging connection between the control volume and the pressure sink insofar as the charging connection comprises the smallest cross-sectional flow area, and</li><li id="ul0010-0002" num="0057">is the charging connection or another charging connection between the control volume and the gas pressure source connection insofar as the discharging connection comprises the smallest cross-sectional flow area. In a further method according to the present disclosure, a pneumatic connection is correspondingly defined.</li></ul></li></ul>

0058As a result, the control volume can be reset by way of the trip valve in the state of the tripping of a drive-in operation. It is consequently not necessary to provide a separate line or connection from the drive-in piston to the control volume or indirect control of a control volume ventilation/venting mechanism by way of a pressure tapped from the drive-in piston. This is possible as according to the present disclosure use is made of the movement of the components of the trip valve which are present in any case in order to bring about the ventilation/venting of the control volume. In addition, an advantage in this case is that the resetting of the control volume is effected in a more secure manner as the resetting is brought about in a more direct manner, and not in an indirect manner by way of the drive-in piston. In certain drive-in situations the drive-in piston could move back into its starting position again too quickly and consequently the gas pressure in the control volume would only be partially reset. The dwelling of the trigger and the workpiece contact element in the pressed or actuated position is slower on account of the direct human interaction and consequently provides a longer time for ventilating/venting the control volume. In general, for example, the contact trip mode is advantageously enabled as a result of resetting the control volume (i.e., moving into the state in which it is situated when the gas pressure is connected, the trigger element not pressed and the workpiece contact element not actuated).

0059In a further exemplified embodiment of the present disclosure, the connection from the loading connection and the discharging connection which comprises the smallest cross-sectional flow area is present both in the first position of the activation element and in the second position of the activation element.

0060As a result, the complexity of the activation element is reduced with reference to said functionality as it does not have to switch between the connections, but is to be able to disconnect and connect only one of said connections. In a preferred manner, the one connection from the loading connection and the discharging connection which comprises the smallest cross-sectional flow area is present in each state of the tool and its components. In a further exemplified embodiment of the present disclosure, the activation element is additionally changeable between the first and the second position by way of the workpiece contact element. In a further method according to the present disclosure, the activation element is additionally changed correspondingly between said two positions by way of the workpiece contact element.

0061As a result, safety is increased even further as the safety device is activatable whenever just the workpiece contact element is activated.

0062In a preferred manner, the activation element is movable into the one position (in a preferred manner the activation position) by the trigger element or the workpiece contact element, i.e., actuation of one of said elements is sufficient, both elements can also be actuated. In contrast, both elements have to be non-actuated so that the activation element is able to assume the other position again.

0063In a further exemplified embodiment of the present disclosure, the activation element is resettable pneumatically into the position from its first and second position in which the activation element is situated in the idle state of the trigger element. In a further method according to the present disclosure, the activation element is moved pneumatically in the direction of the corresponding position.

0064As a result, it is possible to dispense with a resetting spring for the activation element. In a preferred manner, for this purpose the activation element comprises a surface difference of surfaces which are acted upon by gas from the gas pressure source connection less surfaces which are connected to the pressure sink, the surface difference being positive.

0065In a further exemplified embodiment of the present disclosure, the safety device comprises a standby element which is displaceable pneumatically into a safety position and a standby position, wherein the tool is in the secured state when the standby element is in the safety position, and wherein the tool is in the triggered state when the standby element is in the standby position. In a further method according to the present disclosure, the safety device transfers the drive-in tool from the tripped state into the secured state by way of pneumatically displacing a standby element from a standby into a safety position.

0066As a result, a development of the safety device is provided which enables the safety/readiness of the tool by way of pneumatics and the standby element.

0067In a further exemplified embodiment of the present disclosure, the standby element is arranged, in particular in a pneumatic or fluidic manner, between the control volume and the gas pressure source connection and the charging connection is guided through an opening in the standby element. In a further method according to the present disclosure, gas from the gas pressure source connection is guided through an opening in the standby element and on to the control volume.

0068As a result, the control volume is fillable with air by way of the standby element—in contrast to the drive-in tool named in the introduction where the control volume is only filled by way of the operating piston, it is consequently also possible to fill the control volume without any drive-in cycle. In addition, as a result a structure is obtained by way of which pneumatic safety is able to be achieved as the standby element provides part of the charging connection.

0069In a further exemplified embodiment of the present disclosure, the standby element comprises, <ul id="ul0011" list-style="none"><li id="ul0011-0001" num="0000"><ul id="ul0012" list-style="none"><li id="ul0012-0001" num="0070">a first surface region with a first surface area which can be acted upon by gas pressure from the control volume when the trigger element is in its pressed state, and</li><li id="ul0012-0002" num="0071">a second surface region with a second surface area which can be acted upon by gas pressure from the gas pressure source connection when the trigger element is in its pressed state and in a preferred manner when the trigger element is it its idle state;</li><li id="ul0012-0003" num="0072">the first and the second surface regions being set up to direct opposing displacement forces onto the standby element <b>27</b> when acted upon with pressure (for which purpose they comprise in a preferred manner opposing components of surface normals) and the first and second surface region being situated in a common pneumatic volume when the activation element is situated in the first position and being in two separate volumes when the activation element is situated in the second position.</li><li id="ul0012-0004" num="0073">In a further method according to the present disclosure, the standby element is pneumatically displaced over two opposing surface regions and the volumes in which the surface regions are situated in each case are connected together pneumatically (directly, i.e., without substantial flow resistance between them) when the activation element is changed into the first position, and they are separated from one another pneumatically when the activation element is changed into the second position.</li></ul></li></ul>

0074As a result, when the trigger element is situated in its pressed state, the position of the standby element is determined by two antagonistically acting surface regions and the pressure difference between the pressure in the control volume and the pressure in the gas pressure source. As the gas pressure source is substantially constant, the position of the standby element is consequently substantially dependent on the change in pressure in the control volume. As a result of the possibility of connecting the volumes in which the two different surface regions are situated by way of the activation element, very rapid pressure equalization and consequently very rapid resetting of the standby element actively by the user is provided by way of the trigger element (which is coupled with the activation element).

0075In a further exemplified embodiment of the present disclosure, the first surface area is larger than the second surface area.

0076As a result, it is possible to dispense with the use of any springs which press the standby element into an idle position. The position and positioning of the standby element and the time constant realized by the standby element is consequently constant for different gas pressures, which is not possible using a spring element with a spring constant which is not adapted to other gas pressures.

0077In a further exemplified embodiment of the present disclosure, the standby element is realized as a tube piece which is open at both end faces and comprises a central through channel.

0078As a result, an extremely compact design is achieved. In a preferred manner the tube piece comprises different outside diameters. It is displaceably mounted in a valve housing in a preferred manner. The valve housing also comprises in a preferred manner analogously corresponding, different inside diameters. The different diameters enable a simple realization of antagonistically acting surface regions with different surface areas.

0079In a further exemplified embodiment of the present disclosure, the tube piece comprises, along with the through channel, an axial secondary channel which comprises an inner opening, which faces the through channel and in a preferred manner is radial, and an outer opening, which is at an axial spacing from said inner opening, faces the outside surrounding area of the tube piece and in a preferred manner is radial. In a further method according to the present disclosure, a gas flow is directed from the gas pressure source connection through the corresponding axial secondary channel of the tube piece for charging the control volume.

0080As a result, a compact design and advantageous guiding of the charging connection is made possible. In a preferred manner, the two openings in each case form the end of the axial secondary channel.

0081In a further exemplified embodiment of the present disclosure, the activation element together with the standby element are arranged as a trip valve or as part of the trip valve of the trip arrangement in a trip valve housing which is insertable into a tool housing.

0082As a result, the substantial movable parts of the safety device (activation element, standby element) are combined as a compact assembly which is consequently simple to mount, space-saving and/or retro-fittable.

0083In a further exemplified embodiment of the present disclosure, the activation element is movably guided on the standby element and relative to the standby element. In a further method according to the present disclosure, the activation element is guided in a corresponding manner.

0084As a result, a compact design is obtained as the activation element and standby element interact directly with one another in this manner and no additional guiding parts have to be provided. In a preferred manner, the activation element is received by the standby element. In a preferred manner, a contour of the activation element or a sealing element (e.g., sealing rings) of the activation element abuts (directly) against a contour of the standby element or against a sealing element (e.g., sealing ring) of the standby element.

0085In a further exemplified embodiment of the present disclosure, the activation element and the standby element are nested in one another and in a preferred manner are concentric.

0086As a result, the design is very compact. In a particularly preferred manner, the activation element is received concentrically in the standby element which is realized as a tube piece, an outside contour of the activation element or outer sealing elements (e.g., sealing rings) of the activation element abut (directly) against the inside contour of the standby element or against inner sealing elements (e.g., sealing rings) of the standby element.

0087In a further exemplified embodiment of the present disclosure, the activation element is set up in the second position to interrupt the charging connection. In a further method according to the present disclosure, the charging connection is interrupted by the activation element in the second position.

0088As a result, the control volume is disconnected from the gas pressure source by way of the activation element in dependence on the trigger position such that the gas pressure in the control volume is able to be changed from that of the gas pressure source.

0089In a further exemplified embodiment of the present disclosure, the tool comprises a main trip valve and the tool comprises a trip element which is set up to interrupt a pneumatic connection, referred to below as a trip connection, from the gas pressure source connection to the main trip valve when the standby element is in the standby position, and wherein by way of the standby element a pneumatic secondary line is provided between the main trip valve and the gas pressure source connection by bypassing the trip element when the standby element is in the safety position. In a further method according to the present disclosure, a trip connection is correspondingly interrupted by way of a trip element of a main trip valve and a pneumatic secondary line is correspondingly provided.

0090As a result, a trip taking place is pneumatically prevented when the standby element is in the safety position. In contrast, a trip is possible by way of the trip element when the standby element is in the standby position. In a preferred manner, such a secondary line also exists when the standby element is in the standby position and the activation element is not in the activation position. In a preferred manner, the trip element is set up to define a pneumatic trip discharging connection between the main trip valve and a pressure sink (and not only to interrupt the trip connection), when the standby element is in the standby position. As a result, the trip element assumes a double function, as a result of which a compact design is made possible.

0091In a preferred manner, the trigger element comprises a coupling element which can be acted upon by the workpiece contact element, in a preferred manner in any position of the trip element, and which couples the workpiece contact element mechanically with the trip element.

0092The trip element, in a preferred manner, is or includes a pin. In a preferred manner, the trip element comprises sealing surfaces (e.g., sealing rings). The trip element comprises in a preferred manner an idle position and a trip position. In a preferred manner, the trip connection is only interrupted when the activation element is in one of its two positions (e.g., the second position or the activation position) and the trip element is in the trip position. As a result, the activation element also has a trip function when it is moved into the corresponding position, insofar as the trip element is already in the trip position. The trip element, in a preferred manner, is part of the trip valve. The trip element, in a preferred manner, comprises a central axial channel. As a result, a venting line is provided for the preferred permanent connection of the volume which is defined by the rear region of the trip valve housing (see below for more concerning the venting line). The trip element, in a preferred manner, is acted upon at one end by way of a spring in the direction of the trigger element. It can be acted upon at (another) end in a preferred manner by way of a coupling element which is movable as a result of movements of the trigger element and of the workpiece contact element.

0093In a further exemplified embodiment of the present disclosure, the activation element defines part of the trip connection between the gas pressure source connection and the main trip valve.

0094As a result, a very compact design is made possible.

0095In a further exemplified embodiment/method of the present disclosure, the trip element is/will be movably guided on the activation element and relative to the activation element.

0096As a result, a compact design is obtained as the trip element and the activation element interact directly with one another in this manner and no additional guiding parts have to be provided. In a preferred manner, a contour of the activation element or a sealing element (e.g., sealing rings) of the activation element abuts (directly) against a contour of the trip element or against a sealing element (e.g., sealing ring) of the trip element.

0097In a further exemplified embodiment of the present disclosure, the activation element and a trip element for tripping a main trip valve of the tool, in a preferred manner the already named trip element, are nested in one another and in a preferred manner are concentric.

0098As a result, the design is very compact, in particular in the axial direction (direction of movement of the activation element and/or standby element and/or trip element). In a preferred manner, an outside contour of the trip element or outer sealing elements (e.g., sealing rings) of the trip element abut (directly) against the inside contour of the activation element or against inner sealing elements (e.g., sealing rings) of the activation element. The activation element, in a preferred manner, is realized as a tube piece and it guides the trip element within itself.

The present disclosure is now to be further illustrated as an example by way of drawings, in which:

<figref idref="DRAWINGS">FIGS. 1<i>a </i>and 1<i>b </i></figref>show a schematic diagram of a tool according to one example embodiment of the present disclosure,

<figref idref="DRAWINGS">FIG. 2</figref> to <figref idref="DRAWINGS">FIG. 8</figref> show sectional representations of an even more preferred example embodiment of a tool based on <figref idref="DRAWINGS">FIGS. 1<i>a </i>and 1<i>b </i></figref>in different states,

<figref idref="DRAWINGS">FIG. 9</figref> shows a flow diagram of the use of a further preferred example embodiment of a tool of the present disclosure based on the preceding figures in different states which are shown again in part in the preceding figures,

<figref idref="DRAWINGS">FIG. 10</figref> to <figref idref="DRAWINGS">FIG. 12</figref> show, building on the preceding figures, a variant example embodiment of the present disclosure in which the activation element is also displaceable by way of the workpiece contact element,

<figref idref="DRAWINGS">FIG. 13</figref> shows a flow diagram for said variant of <figref idref="DRAWINGS">FIG. 10</figref> to <figref idref="DRAWINGS">FIG. 12</figref>,

<figref idref="DRAWINGS">FIG. 14</figref> to <figref idref="DRAWINGS">FIG. 20</figref> show a further variant of the present disclosure shown in <figref idref="DRAWINGS">FIG. 1</figref> to <figref idref="DRAWINGS">FIG. 9</figref>, wherein the control volume <b>15</b> is realized by the trip valve <b>20</b>,

<figref idref="DRAWINGS">FIGS. 21<i>a </i>to 24<i>b </i></figref>show different arrangements according to the present disclosure of the smallest cross sectional flow area which defines the delay time of the safety device.

0107<figref idref="DRAWINGS">FIGS. 1<i>a </i>and 1<i>b </i></figref>show a schematic diagram of a tool <b>1</b> according to one example embodiment of the present disclosure for driving fasteners such as fastener <b>90</b> into a workpiece such as workpiece <b>91</b>. The tool <b>1</b> comprises: <ul id="ul0013" list-style="none"><li id="ul0013-0001" num="0000"><ul id="ul0014" list-style="none"><li id="ul0014-0001" num="0108">an actuator unit <b>3</b>, by way of which the fasteners <b>90</b> are drivable into the workpiece <b>91</b> in drive-in cycles,</li><li id="ul0014-0002" num="0109">a trip arrangement <b>5</b>, by way of which the drive-in cycles of the actuator unit <b>3</b> are trippable, wherein the trip arrangement <b>5</b> comprises a trigger element <b>6</b> which is manually operable and comprises an idle state <b>600</b> (shown in <figref idref="DRAWINGS">FIG. 1<i>a</i></figref>) and a pressed state <b>601</b> (shown in <figref idref="DRAWINGS">FIG. 1<i>b</i></figref>), wherein the trip arrangement <b>5</b> additionally comprises a workpiece contact element <b>7</b> which is actuatable by placing the drive-in tool <b>1</b> onto the workpiece <b>91</b>,</li><li id="ul0014-0003" num="0110">a gas pressure source connection <b>23</b> to which a gas pressure source is connectable,</li><li id="ul0014-0004" num="0111">a safety device <b>8</b> which is coupled with the trigger element <b>6</b> and is set up to bring about a transfer of the drive-in tool <b>1</b> from a trip-ready state into a secured state after expiry of a delay time which proceeds from an activation of the safety device <b>8</b>,</li><li id="ul0014-0005" num="0112">wherein the safety device <b>8</b> comprises a control volume <b>15</b>,</li><li id="ul0014-0006" num="0113">wherein the safety device <b>8</b> comprises an activation element <b>33</b> which is changeable between a first and a second position by way of the trigger element <b>6</b>.</li></ul></li></ul>

0114In the first position of the activation element <b>33</b>, a pneumatic connection is defined between the control volume <b>15</b> and the gas pressure source connection <b>23</b>, which is hereafter referred to as charging connection <b>27</b>.<b>1</b>. In the second position of the activation element <b>33</b> a pneumatic connection is defined between the control volume <b>15</b> and a pressure sink <b>40</b>, which is hereafter referred to as discharging connection <b>33</b>.<b>1</b>. One connection from the charging connection <b>27</b>.<b>1</b> and the discharging connection <b>33</b>.<b>1</b>, here the discharging connection <b>33</b>.<b>1</b>, comprises a smallest cross-sectional flow area <b>33</b>.<b>8</b> which, together with a gas pressure of the gas pressure source, determines the delay time of the safety device.

0115In this case, the safety device <b>8</b> of the tool <b>1</b> functions as follows. In <figref idref="DRAWINGS">FIG. 1<i>a</i></figref>, the control volume <b>15</b> is charged by way of the charging connection <b>27</b>.<b>1</b>. If the user, proceeding from <figref idref="DRAWINGS">FIG. 1<i>a</i></figref>, presses the trigger <b>6</b>, the activation element <b>33</b> is displaced such that the charging connection <b>27</b>.<b>1</b> is disconnected and the discharging connection <b>33</b>.<b>1</b> is established (<figref idref="DRAWINGS">FIG. 1<i>b</i></figref>). As a result of the small cross sectional flow area of the discharging connection <b>33</b>.<b>1</b>, the control volume <b>15</b> is discharged slowly, i.e., at the determined delay time. Dependent on the pressure in the control volume <b>15</b>, the tool <b>1</b> is then moved into a trip-ready state or a secured state.

0116These figures additionally show one preferred development, according to which the correspondingly other connection from the charging connection <b>27</b>.<b>1</b> and the discharging connection <b>33</b>.<b>1</b>, i.e., here the charging connection <b>27</b>.<b>1</b>, comprises a larger smallest cross sectional flow area than the one connection from the charging connection <b>27</b>.<b>1</b> and the discharging connection <b>33</b>.<b>1</b>, i.e., here the discharging connection <b>33</b>.<b>1</b>, as a result of which the control volume <b>15</b> is able to be charged very rapidly.

0117In addition, one preferred development is illustrated, according to which the tool <b>1</b> comprises a pneumatic line which is both part of the charging connection <b>27</b>.<b>1</b> and part of the discharging connection <b>33</b>.<b>1</b> and which extends from the activation element <b>33</b> toward the control volume <b>15</b>. In this case, the tool <b>1</b> additionally comprises two lines which are separate from one another, wherein one of the lines which are separate from one another is part of the charging connection <b>27</b>.<b>1</b> and extends from the activation element <b>33</b> toward the gas pressure source connection <b>23</b>, and the other of the lines which are separate from one another is part of the discharging connection <b>33</b>.<b>1</b> and extends from the activation element <b>33</b> toward the pressure sink <b>40</b>. The smallest cross sectional flow area <b>33</b>.<b>8</b>, which, together with the gas pressure, determines the delay time of the safety device <b>8</b>, is present in precisely one of the lines which are separate from one another, here in the line which extends from the activation element <b>33</b> toward the pressure sink <b>40</b>. The rapid charging and slow discharging of the control volume <b>15</b> is realized structurally in a very advantageous manner as a result.

0118Further preferred developments are provided herein, namely that the safety device <b>8</b> is set up to transfer the tool <b>1</b> into the secured state if a pressure threshold in the control volume is fallen below and that the charging connection <b>27</b>.<b>1</b> is present when the trigger element <b>6</b> is in its idle state <b>600</b>.

0119<figref idref="DRAWINGS">FIG. 2</figref> to <figref idref="DRAWINGS">FIG. 8</figref> show sectional representations of an even more preferred embodiment of a tool <b>1</b> based on <figref idref="DRAWINGS">FIGS. 1<i>a </i>and 1<i>b </i></figref>in different states. It has the features described and shown in <figref idref="DRAWINGS">FIG. 1<i>a </i></figref>and <figref idref="DRAWINGS">FIG. 1</figref><i>b. </i>

0120Provided herein additionally are the following preferred features which are also usually present in the case of a compressed air drive-in tool, but are not absolutely necessary and which also interact well with various features of the present disclosure in an alternative form: <ul id="ul0015" list-style="none"><li id="ul0015-0001" num="0000"><ul id="ul0016" list-style="none"><li id="ul0016-0001" num="0121">the trigger element <b>6</b> is a trigger lever which is pivotably mounted on a trigger element axis <b>6</b><i>a; </i></li><li id="ul0016-0002" num="0122">the actuator unit <b>3</b> comprises an operating cylinder <b>10</b> in which is guided an operating piston <b>11</b> which moves a drive-in punch <b>9</b>; and</li><li id="ul0016-0003" num="0123">a drive volume <b>13</b> is present on the side of the operating piston <b>11</b> on the other side of the drive-in punch <b>9</b>.</li></ul></li></ul>

0124<figref idref="DRAWINGS">FIGS. 2 and 3</figref> show the tool <b>1</b> when the compressed air is not connected, the standby element <b>27</b> is situated in the safety position. <figref idref="DRAWINGS">FIG. 4</figref> shows the tool <b>1</b> with the compressed air connected, neither the trigger element <b>6</b> nor the workpiece contact element <b>7</b> being actuated, and wherein the standby element <b>27</b> is situated in the standby position. <figref idref="DRAWINGS">FIG. 5</figref> shows the tool <b>1</b> with the trigger element <b>6</b> pressed and with the standby element <b>27</b> still in the standby position. <figref idref="DRAWINGS">FIG. 6</figref> shows the tool <b>1</b> after the predetermined time has elapsed and the tool <b>1</b> has been transferred into the secured state, wherein the standby element <b>27</b> is now situated in the safety position. <figref idref="DRAWINGS">FIG. 7</figref> shows the tool <b>1</b> in the state of tripping a drive-in operation, wherein the standby element <b>27</b> in this case is in the standby position. <figref idref="DRAWINGS">FIG. 8</figref> shows the tool with the trigger element <b>6</b> and the workpiece contact element <b>7</b> pressed, it being situated in the secured state, and wherein the standby element <b>27</b> is situated in the safety position, and consequently wherein no drive-in operation is tripped.

0125The activation element <b>33</b> is resettable pneumatically in the position from its first and second position in which the activation element <b>33</b> is situated in the idle state <b>600</b> of the trigger element <b>6</b>. The activation element <b>33</b> comprises a positive surface difference between surfaces which are acted upon by gas from the gas pressure source connection less surfaces which are connected to the pressure sink <b>40</b>.

0126The safety device <b>8</b> comprises a standby element <b>27</b> which is displaceable pneumatically into a safety position and a standby position. The tool <b>1</b> is situated in the secured state (shown in <figref idref="DRAWINGS">FIGS. 2, 3, 6, and 8</figref>) when the standby element <b>27</b> is situated in the safety position, and it is situated in the trip-ready state <b>100</b> (shown in <figref idref="DRAWINGS">FIGS. 4, 5, and 7</figref>) when the standby element <b>27</b> is situated in the standby position. The standby element <b>27</b> is arranged between the control volume <b>15</b> and the gas pressure source <b>23</b> and the charging connection <b>27</b>.<b>1</b> is guided through at least two openings in the standby element <b>27</b> (<figref idref="DRAWINGS">FIG. 4</figref>). The standby element <b>27</b> comprises a first surface region with a first surface area A<b>1</b> which can be acted upon by gas pressure from the control volume <b>15</b> when the trigger element <b>6</b> is in its pressed state <b>601</b>. It comprises a second surface region with a second surface area A<b>2</b> which can be acted upon with gas from the gas pressure source when trigger element <b>6</b> is in its pressed state <b>601</b> and when trigger element <b>6</b> is in its idle state <b>600</b>. The first and the second surface regions are set up to direct opposing displacement forces onto the standby element <b>27</b> when acted upon with pressure. They comprise opposing components of surface normals for this purpose. The first and second surface regions are situated in a common pneumatic volume when the activation element <b>33</b> is situated in the first position (to the left, or in the position closer to the trigger element) and are situated in two separate volumes when the activation element <b>33</b> is situated in the second position (to the right, or further away from the trigger element). The first surface area A<b>1</b> is greater than the second surface area A<b>2</b>. The standby element <b>27</b> is realized as a tube piece which is open at both end faces and comprises a central through channel <b>27</b>.<b>3</b>. The tube piece comprises, along with the through channel <b>27</b>.<b>3</b>, an axial secondary channel <b>27</b>.<b>4</b> which comprises an opening which faces the through channel <b>27</b>.<b>3</b> and one which is at an axial spacing therefrom and faces the outside surrounding area of the tube piece. The secondary channel <b>27</b>.<b>4</b> is part of the charging connection <b>27</b>.<b>1</b> (<figref idref="DRAWINGS">FIG. 4</figref>). The activation element <b>33</b> is guided movably on the standby element <b>27</b> and relative to the standby element <b>27</b>. The activation element <b>33</b> and the standby element <b>27</b> are nested in one another and are concentric. Outer sealing rings <b>33</b>.<b>2</b>, <b>33</b>.<b>3</b>, <b>33</b>.<b>4</b>, <b>33</b>.<b>5</b>, <b>33</b>.<b>6</b>, and <b>33</b>.<b>7</b> of the activation element <b>33</b> abut directly against the inside contour of the standby element <b>27</b>. The activation element <b>33</b> is also realized as a tube piece. The discharging connection <b>33</b>.<b>1</b> extends through two openings in the activation element <b>33</b>, present in a lateral surface of the activation element <b>33</b>.<b>1</b> (<figref idref="DRAWINGS">FIG. 5</figref>). The discharging connection <b>33</b>.<b>1</b> is defined in the activation position (second position, on the right) by the activation element <b>33</b>.

0127The tool <b>1</b> comprises a main trip valve <b>12</b> and a trip element <b>21</b> which is set up to interrupt a pneumatic trip connection <b>21</b>.<b>1</b> (<figref idref="DRAWINGS">FIG. 5</figref>) from the gas pressure source connection <b>23</b> to the main trip valve <b>12</b> when the standby element <b>27</b> is in the standby position. By way of the standby element <b>27</b>, a pneumatic secondary line <b>27</b>.<b>2</b> is provided between the main trip valve <b>12</b> and the gas pressure source connection <b>23</b> by bypassing the trip element <b>21</b> when the standby element <b>27</b> is in the safety position (<figref idref="DRAWINGS">FIG. 6</figref>) or when the activation element <b>33</b> is in the first position, to the left (<figref idref="DRAWINGS">FIG. 4</figref>). The activation element <b>33</b> defines part of the trip connection <b>21</b>.<b>1</b> from the gas pressure source connection <b>23</b> to the main trip valve <b>12</b> (<figref idref="DRAWINGS">FIG. 5</figref>). The trip element <b>21</b> is guided movably on the activation element <b>33</b> and relative to the activation element <b>33</b>. The activation element <b>33</b> and the trip element <b>21</b> are nested in one another. The trip element <b>21</b> is set up here to define a pneumatic trip discharging connection <b>21</b>.<b>2</b> between the main trip valve <b>12</b> and the pressure sink <b>40</b>.

0128The trigger element <b>6</b> comprises a coupling element <b>26</b> which can be acted upon by the workpiece contact element <b>7</b> in each position of the trip element <b>21</b> and which couples the workpiece contact element <b>7</b> and the trigger element <b>6</b> mechanically with the trip element <b>21</b>.

0129In addition, the following advantageous, optional specifications are shown here: <ul id="ul0017" list-style="none"><li id="ul0017-0001" num="0000"><ul id="ul0018" list-style="none"><li id="ul0018-0001" num="0130">in order to enable continuous contact tripping (trigger element <b>6</b> held in the pressed state, workpiece contact element <b>7</b> actuated repeatedly at short intervals, shorter than the predetermined time), the operating cylinder <b>10</b> comprises a ventilation arrangement <b>18</b> produced from at least one, here several openings <b>18</b><i>a </i>in the lateral surface which are covered radially outward (with reference to the operating cylinder <b>10</b>) by way of a resilient sealing ring <b>18</b><i>b </i>which acts as a one-way valve; the ventilation arrangement <b>18</b> is arranged in a portion <b>14</b> of the operating cylinder <b>10</b> which is located on the other side of the drive volume <b>13</b> in the idle position with reference to the operating piston <b>11</b>; compressed air is directed into the control volume in this way via the openings <b>18</b><i>a </i>as a result of a drive-in operation; the countdown of the safety device <b>8</b> is reset in this way even when the trigger element <b>6</b> is kept continuously pressed;</li><li id="ul0018-0002" num="0131">elements (in particular <b>27</b>, <b>33</b>, and <b>21</b>) of the safety device <b>8</b> are combined as a trip valve <b>20</b> of the trip arrangement <b>5</b>, the trip valve <b>20</b> being arranged in a preferred manner in the handle portion <b>24</b> of the tool <b>1</b>—in this respect the trip valve <b>20</b> itself can also be viewed as part of the safety device <b>8</b>; the trip valve comprises a housing <b>20</b>.<b>1</b> in which the standby element <b>27</b> is displaceably mounted with sealing elements, here sealing rings; the activation element <b>33</b> and the trip element <b>21</b> are additionally accommodated in the housing <b>20</b>.<b>1</b>; a pneumatic line <b>12</b><i>a </i>leads from the trip valve <b>20</b> to the main trip valve <b>12</b> (only the start of said line can be seen here at the trip valve <b>20</b>, the rest of the line <b>12</b><i>a </i>is concealed); a valve inlet <b>22</b> is present in the housing <b>20</b>.<b>1</b> on the gas source side and a valve inlet <b>30</b> on the control volume side; between the valve inlet <b>30</b> on the control volume side and the control volume <b>15</b> there is a ventilation/venting line, by way of which the control volume <b>15</b> is able to be ventilated or vented by way of the trip valve <b>20</b>;</li><li id="ul0018-0003" num="0132">a trip element spring <b>21</b><i>a </i>pre-stresses the trip element <b>21</b> into its idle position (to the left).</li></ul></li></ul>

0133<figref idref="DRAWINGS">FIG. 9</figref> shows a flow diagram of the use of the further preferred embodiment of a tool based on the preceding figures in different states which are shown in part in the preceding figures (cross-referenced by Roman numerals). In each case states are shown in circles and events in squares.

0134In state I, the tool <b>1</b> is not connected to the gas pressure source. Consequently, the tool is situated in the secured state <b>101</b>. The trigger element <b>6</b> is situated in the idle state <b>600</b> and the workpiece contact element <b>7</b> is in the non-actuated state <b>700</b>. The safety device <b>8</b> is not active, i.e., a time counter is not running. In said state, the standby element <b>27</b> can be situated either in the safety position (left position) or in the standby position (right position).

0135In the state II, the tool <b>1</b> is then in use by connecting <b>230</b> it to the gas pressure source, as a result of which the instrument assumes the trip-ready state <b>100</b>. In this case, the standby element <b>27</b> (unless it was not already situated there in state I) is moved into its standby position. This is brought about by the surface difference between the surface regions A<b>1</b> and A<b>2</b> which, in said state, are both acted upon by the pressure from the gas pressure source. The control volume <b>15</b> is “charged” with gas pressure via the charging connection <b>27</b>.<b>1</b>. In addition, in said state there is a secondary line <b>27</b>.<b>2</b> which bridges the trip element <b>21</b>. The secondary line <b>27</b>.<b>2</b> is consequently a connection, which cannot be interrupted by the trip element <b>21</b>, from the gas pressure source connection <b>23</b> to the main trip valve <b>12</b>.

0136Proceeding from said state II, by actuating <b>710</b> the workpiece contact element <b>7</b> (e.g., placing and pressing the tool tip onto a workpiece) a next sequence state can be achieved (on the left, second line) where the workpiece contact element <b>7</b> is then situated in its actuated state <b>701</b>.

0137Proceeding from said state, by actuating <b>610</b> the trigger element <b>6</b>, the state V is achieved or by raising <b>720</b> the workpiece contact element <b>7</b> state II is resumed.

0138In the state V, a drive-in cycle is tripped (indicated by the double border). The trigger element <b>6</b> is situated in the pressed state <b>601</b> and the workpiece contact element <b>7</b> in the actuated state <b>701</b>. The trip element <b>21</b> is in its trip position, which is achieved by way of the coupling element <b>26</b>. By both the trigger element <b>6</b> and the workpiece contact element <b>7</b> in said state V being situated in their actuated or pressed states in each case, the trip connection <b>21</b>.<b>1</b> is established from the main trip valve <b>12</b> to the pressure sink <b>40</b> such that the main trip valve <b>12</b> is activated and the drive-in operation is carried out. In this case, the drive volume <b>13</b> is acted upon with the gas pressure from the gas pressure source such that the operating piston is moved in the direction of the tool tip (to the left). It passes the ventilation arrangement <b>18</b>, as a result of which the control volume <b>15</b> is also acted upon with gas pressure from the gas pressure source via the openings <b>18</b><i>a</i>. From said state V, the previous state is achieved by releasing <b>620</b> the trigger element <b>6</b> (on the left, second line) or the state III is achieved by raising <b>720</b> the workpiece contact element <b>7</b>. The raising <b>720</b> simultaneously initiates an activation <b>810</b> of the safety device <b>8</b>, as a result of which a countdown starts for displacing the tool <b>1</b> into the secured state <b>101</b>. For by way of the raising <b>720</b>, the operating piston <b>11</b> is moved into its idle position again such that the control volume <b>15</b> is then no longer able to be charged by way of the ventilation arrangement <b>18</b>—the resilient ring, in this case, prevents discharging in the direction of the operating cylinder <b>10</b>. As the trigger element <b>6</b> is pressed <b>601</b>, and consequently the discharging connection <b>33</b>.<b>1</b> is established, the pressure in the control volume <b>15</b> is gradually reduced, i.e., the countdown is running and the safety device <b>8</b> is activated.

0139In the state III, by actuating <b>610</b> the trigger element <b>6</b> the state II is additionally achieved, as a result of which the safety device <b>8</b> is also activated and consequently a countdown to displace the tool <b>1</b> into the secured state <b>101</b> is started. The control volume <b>15</b>, in this case, has been charged by the charging connection <b>27</b>.<b>1</b> in the state II and is then slowly discharged by way of the discharging connection <b>33</b>.<b>1</b>.

0140In the state III, the control volume <b>15</b> is separated from the gas pressure source (whilst, for example, in state II a connection has existed between the same via the charging connection <b>27</b>.<b>1</b>) and air escapes via the discharging connection <b>33</b>.<b>1</b> such that the standby element <b>27</b> moves abruptly in the direction of the safety position once a certain time has elapsed.

0141If the trigger element <b>6</b> is then released <b>620</b>, state II is resumed. In this case, the control volume <b>15</b> is reconnected to the gas pressure of the gas pressure source and the charging connection <b>27</b>.<b>1</b> and the discharging connection <b>33</b>.<b>1</b> are separated. The standby element <b>27</b> is displaced back into the standby position and remains there.

0142If, on the other hand, the workpiece contact element <b>7</b> is actuated <b>710</b>, the state V is resumed and a drive-in cycle takes place. The actuation <b>710</b> causes the trip element <b>20</b> to be displaced into the trip position (right position) by way of the coupling element <b>26</b> such that the trip connection <b>21</b>.<b>2</b> is re-established.

0143If, in contrast, state III is maintained longer than the predetermined time, i.e., an elapsing <b>820</b> of the predetermined time is expected, the state IV is achieved.

0144In the state IV, the standby element <b>27</b> has arrived in the safety position (left position). The standby element <b>27</b> in said position allows for a secondary line <b>27</b>.<b>2</b> which connects the main trip valve <b>12</b> to the gas pressure of the gas pressure source such that, irrespective in which position the trip element <b>21</b> or the activation element <b>33</b> are situated, it is not possible to interrupt said connection. An interruption would be possible, however, in order to trip a drive-in operation. Consequently, tripping is impossible and consequently the tool <b>1</b> is situated in the secured position <b>101</b>. Activation <b>710</b> of the workpiece contact element <b>7</b>, which leads into the state VI and displaces the trip element into its trip position, cannot produce any tripping either as the secondary line <b>27</b>.<b>2</b> is defined by the standby element <b>27</b>. In order to get out of the secured state <b>101</b> again, the user has to release <b>620</b> the trigger element <b>6</b>. Thus the state IV is left and the state II is resumed or the state VI is left and the state which is shown in the second line on the left is resumed. By releasing <b>620</b> the trigger <b>6</b>, the control volume <b>15</b> is reconnected to the gas pressure source and the standby element <b>27</b> is displaced into the standby position, as the activation element <b>33</b> is displaced pneumatically back again into the left position when the trigger <b>6</b> is released and then the charging connection <b>27</b>.<b>1</b> is re-established.

0145<figref idref="DRAWINGS">FIG. 10</figref> to <figref idref="DRAWINGS">FIG. 12</figref> show, building on the preceding figures, a variant in which the activation element <b>33</b> is also displaceable by way of the workpiece contact element <b>7</b>. The workpiece contact element <b>7</b> is coupled mechanically with the activation element <b>33</b> in such a manner that the workpiece contact element <b>7</b> is able to press the activation element <b>33</b> into the activation position (right position); said state is shown in <figref idref="DRAWINGS">FIGS. 11 and 12</figref>, the standby element <b>27</b> being situated in the standby position in <figref idref="DRAWINGS">FIG. 11</figref> and in the safety position in <figref idref="DRAWINGS">FIG. 12</figref>. Said additional mechanical coupling with the activation element <b>33</b> is indicated here as an example and in a rough manner by way of an angled region of the workpiece contact element <b>7</b>. The workpiece contact element <b>7</b> is set up in the same way as previously to press the trip element <b>21</b> by way of the coupling element <b>26</b>. Only if both elements from the trigger element <b>6</b> and the workpiece contact element <b>7</b> are not actuated or are in the idle state is the activation element <b>33</b> able to move out of the activation position.

0146<figref idref="DRAWINGS">FIG. 13</figref> shows a flow diagram for said variant in <figref idref="DRAWINGS">FIGS. 10 to 12</figref>, once again states being referenced with Roman numerals—the states II-VI, in this case, can be taken from <figref idref="DRAWINGS">FIGS. 2 to 8</figref>, just the changed mechanical coupling between the activation element <b>33</b> and the workpiece contact element <b>7</b> providing a difference, the state otherwise, however, being the same. The sequence builds on the sequence shown in <figref idref="DRAWINGS">FIG. 9</figref>; in contrast to this, the safety device <b>8</b> is now already activated by way of actuating <b>710</b> the workpiece contact element <b>7</b> such that it is now situated in the activated state <b>801</b> in the state VII, for the activation element <b>33</b> is displaced by the workpiece contact element <b>7</b> into the activation position, left position, such that the discharging connection <b>33</b>.<b>1</b> is established. Consequently, it is possible for the predetermined time to run out <b>820</b> already from state VII and the tool is transferred into the secured state <b>101</b>, which leads overall to the state VIII which is new compared to <figref idref="DRAWINGS">FIG. 9</figref>, as now a secured state <b>101</b> can also be achieved when the trigger element <b>6</b> is situated in the non-pressed state <b>600</b>. Another difference is that it is now no longer possible proceeding from the state VI by releasing <b>620</b> the trigger element <b>6</b> for the tool to be transferred back into a trip-ready state <b>100</b>, for, as a general rule, it is only possible to transfer into the trip-ready state <b>100</b> when both the trigger element <b>6</b> and the workpiece contact element <b>7</b> are moved into the non-actuated or non-pressed state.

0147<figref idref="DRAWINGS">FIG. 14</figref> to <figref idref="DRAWINGS">FIG. 20</figref> show a variant according to the present disclosure of the tool according to the present disclosure shown in <figref idref="DRAWINGS">FIG. 1</figref> to <figref idref="DRAWINGS">FIG. 9</figref>, in contrast thereto the control volume <b>15</b> being realized by the trip valve <b>20</b>. Otherwise the states marked in <figref idref="DRAWINGS">FIG. 14</figref> to <figref idref="DRAWINGS">FIG. 19</figref> with Roman numerals also correspond to the states in <figref idref="DRAWINGS">FIGS. 2 to 9</figref> and also the flow diagram in <figref idref="DRAWINGS">FIG. 9</figref> retains its validity. In addition, it is possible to provide the modification according to <figref idref="DRAWINGS">FIGS. 10 to 12</figref> also for said variant, i.e., the activation element <b>33</b> is also displaceable just by way of the workpiece contact element <b>7</b> and consequently the flow diagram from <figref idref="DRAWINGS">FIG. 13</figref> is to be used.

0148In comparison with preceding variants there are the following differences: <ul id="ul0019" list-style="none"><li id="ul0019-0001" num="0000"><ul id="ul0020" list-style="none"><li id="ul0020-0001" num="0149">the control volume <b>15</b> is reduced to the region also already present previously inside the trip valve housing <b>20</b>.<b>1</b> which adjoins the surface region A<b>1</b>. No separate volume adjoining the drive-in piston <b>10</b> is necessary and consequently no special valve inlet <b>30</b> on the control volume side and no ventilation arrangement <b>18</b> arranged on the operating cylinder <b>10</b> either. As these are not present, as a rule, in the case of existing former tool housings, on account of said trip valve <b>20</b> former tool housings are easily able to be retrofitted with the safety device <b>8</b>.</li><li id="ul0020-0002" num="0150">The trip valve <b>20</b>, when the tool <b>1</b> is situated in the trip-ready state <b>100</b> and the trigger element <b>6</b> is situated in the pressed state <b>601</b> and at the same time the workpiece contact element <b>7</b> is actuated (see <figref idref="DRAWINGS">FIG. 18</figref>, state V), then defines a pneumatic connection. Said connection is a further charging connection <b>27</b>.<b>3</b> between the control volume <b>15</b> and the gas pressure source connection <b>23</b>, as the discharging connection <b>33</b>.<b>1</b> comprises the smallest cross sectional flow area <b>33</b>.<b>8</b>. The control volume <b>15</b> is filled with pressure again by way of said charging connection <b>27</b>.<b>3</b>, as a result of which the elapsed delay time is reset. I.e., each time a drive-in operation is tripped (corresponds to state V) the safety device <b>8</b> is reset again in this way directly by way of the trip valve <b>20</b>.</li><li id="ul0020-0003" num="0151">The discharging connection <b>33</b>.<b>1</b>, which also comprises the smallest cross sectional flow area <b>33</b>.<b>8</b>, is present both in the first position of the activation element <b>33</b> and in the second position of the activation element <b>33</b>. In addition, the smallest cross sectional flow area <b>33</b>.<b>8</b> is variable by way of an adjusting needle <b>34</b>.<b>1</b> which forms a needle valve <b>34</b> and the cross sectional flow area is consequently very finely adjustable. The needle valve <b>34</b> is shown in detail in <figref idref="DRAWINGS">FIG. 20</figref>. The adjusting needle <b>34</b>.<b>2</b> is arranged on an adjusting screw <b>34</b>.<b>1</b>. The adjusting screw <b>34</b>.<b>1</b> is screwed into a suitable thread of the housing <b>20</b>.<b>1</b> such that the adjusting needle <b>34</b>.<b>2</b> projects into an opening of the housing <b>20</b>.<b>1</b>, the cross sectional flow area of which is consequently variable as a result of rotating the adjusting screw <b>34</b>.<b>1</b>. A preferred anti-twist ring <b>34</b>.<b>3</b> protects the adjusting screw <b>34</b>.<b>3</b> from unwanted rotation. After the needle valve <b>34</b> in a groove, the gas then escapes past a dowel pin <b>28</b>, by way of which the trip valve housing is secured in the tool housing, to the atmosphere (pressure sink <b>40</b>)—this is only indicated here as in said drawing plane the dowel pin <b>28</b> fills out the groove for the dowel pin in a substantial manner, which, however, is not so in another drawing plane, as a result of which sufficient space is then provided there for the air flow.</li></ul></li></ul>

0152<figref idref="DRAWINGS">FIGS. 21<i>a </i>to 24<i>b </i></figref>show schematic diagrams of arrangements according to the present disclosure of the smallest cross sectional flow area which defines the delay time of the safety device. These are in each case pairs of figures (a and b), in the respective figure b the activation element <b>33</b> being shown in the activation position, i.e., in the position in which the delay time starts to run down. The other position of the activation element <b>33</b> is then shown in the respective figure a.

0153The smallest cross sectional flow area <b>33</b>.<b>8</b>, which, together with the gas pressure, determines the delay time of the safety device <b>8</b>, is arranged in precisely one of the following pneumatic connections: <ul id="ul0021" list-style="none"><li id="ul0021-0001" num="0000"><ul id="ul0022" list-style="none"><li id="ul0022-0001" num="0154">in a pneumatic connection between the activation element <b>33</b> and the gas pressure source connection <b>23</b>—as is shown in <figref idref="DRAWINGS">FIGS. 22</figref><i>a/b; </i></li><li id="ul0022-0002" num="0155">in a pneumatic connection between the activation element <b>33</b> and the pressure sink <b>40</b>—as is shown in <figref idref="DRAWINGS">FIGS. 21</figref><i>a/b </i>and <figref idref="DRAWINGS">FIGS. 1 to 13</figref>;</li><li id="ul0022-0003" num="0156">in a pneumatic connection which exists in both the first position and the second position of the activation element <b>33</b> between the control volume <b>15</b> and the gas pressure source connection <b>23</b>—as is shown in <figref idref="DRAWINGS">FIGS. 23</figref><i>a/b; </i></li><li id="ul0022-0004" num="0157">in a pneumatic connection which exists in both the first position and the second position of the activation element <b>33</b> between the control volume <b>15</b> and the pressure sink <b>40</b>—as is shown in <figref idref="DRAWINGS">FIGS. 24</figref><i>a/b </i>and <figref idref="DRAWINGS">FIGS. 14 to 20</figref>.</li></ul></li></ul>

0158As a result, by way of the said arrangements in which in each case the smallest cross sectional flow area <b>33</b>.<b>8</b> is not located in a region which is utilized in a line portion which is common to a charging connection <b>27</b>.<b>1</b> and a discharging connection <b>33</b>.<b>1</b>, rapid resetting of the pressure in the control volume <b>15</b> is made possible by releasing the trigger element <b>6</b> such that the tool <b>1</b> is also rapidly transferable (quicker than the delay time) from the secured state <b>101</b> into the standby state <b>100</b> again. <figref idref="DRAWINGS">FIGS. 22</figref><i>a/b </i>and <b>23</b><i>a/b </i>show configurations where the safety device <b>8</b> transfers the tool <b>1</b> into the secured state <b>101</b> when a pressure threshold in the control volume <b>15</b> is exceeded, whilst <figref idref="DRAWINGS">FIGS. 21</figref><i>a/b </i>and <figref idref="DRAWINGS">FIGS. 24</figref><i>a/b </i>along with <figref idref="DRAWINGS">FIGS. 1 to 20</figref> show configurations where the safety device <b>8</b> transfers the tool <b>1</b> into the secured state <b>101</b> when a pressure threshold in the control volume <b>15</b> is fallen below.

0159<tables id="TABLE-US-00001" num="00001"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="1"><colspec colname="1" colwidth="217pt" align="center" /><thead><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row><row><entry>List of references</entry></row><row><entry namest="1" nameend="1" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="1" colwidth="63pt" align="left" /><colspec colname="2" colwidth="154pt" align="left" /><tbody valign="top"><row><entry> 1</entry><entry>Drive-in tool</entry></row><row><entry> 3</entry><entry>Actuator unit</entry></row><row><entry> 5</entry><entry>Trip arrangement</entry></row><row><entry> 6</entry><entry>Trigger element</entry></row><row><entry> 6a</entry><entry>Trigger element axis</entry></row><row><entry> 7</entry><entry>Workpiece contact element</entry></row><row><entry> 8</entry><entry>Safety device</entry></row><row><entry> 9</entry><entry>Drive-in punch</entry></row><row><entry> 10</entry><entry>Operating cylinder</entry></row><row><entry> 11</entry><entry>Operating piston</entry></row><row><entry> 12</entry><entry>Main trip valve</entry></row><row><entry> 12a</entry><entry>Line to the main trip valve</entry></row><row><entry> 13</entry><entry>Drive volume</entry></row><row><entry> 14</entry><entry>The portion of the operating cylinder located on</entry></row><row><entry /><entry>the other side of the drive volume with reference</entry></row><row><entry /><entry>to the operating piston</entry></row><row><entry> 15</entry><entry>Control volume</entry></row><row><entry> 18</entry><entry>Ventilation arrangement</entry></row><row><entry> 18a</entry><entry>Openings</entry></row><row><entry> 18b</entry><entry>Resilient ring</entry></row><row><entry> 19</entry><entry>Ventilation/venting line</entry></row><row><entry> 20</entry><entry>Trip valve</entry></row><row><entry> 20.1</entry><entry>Housing</entry></row><row><entry> 21</entry><entry>Trip element</entry></row><row><entry> 21.1</entry><entry>Trip connection</entry></row><row><entry> 21.2</entry><entry>Trip discharging connection</entry></row><row><entry> 21a</entry><entry>Trip element spring</entry></row><row><entry> 22</entry><entry>Valve inlet on the gas source side</entry></row><row><entry> 23</entry><entry>Gas pressure source connection</entry></row><row><entry> 24</entry><entry>Handle portion</entry></row><row><entry> 26</entry><entry>Coupling element</entry></row><row><entry> 27</entry><entry>Standby element</entry></row><row><entry> 27.1</entry><entry>Charging connection</entry></row><row><entry> 27.2</entry><entry>Secondary line</entry></row><row><entry> 27.3</entry><entry>Central through channel</entry></row><row><entry> 27.4</entry><entry>Axial secondary channel</entry></row><row><entry> 27.5</entry><entry>Further charging connection</entry></row><row><entry> 28</entry><entry>Dowel pin</entry></row><row><entry> 30</entry><entry>Valve inlet on the control volume side</entry></row><row><entry> 33</entry><entry>Activation element</entry></row><row><entry> 33.1</entry><entry>Discharging connection</entry></row><row><entry>33.2, 33.3, 33.4,</entry><entry>Sealing rings of the activation element</entry></row><row><entry>33.5, 33.6, 33.7</entry></row><row><entry> 33.8</entry><entry>Smallest cross sectional flow area which, together</entry></row><row><entry /><entry>with the gas pressure of the gas pressure source,</entry></row><row><entry /><entry>determines the delay time of the safety device</entry></row><row><entry> 34</entry><entry>Needle valve</entry></row><row><entry> 34.1</entry><entry>Adjusting screw</entry></row><row><entry> 34.2</entry><entry>Adjusting needle</entry></row><row><entry> 34.3</entry><entry>Anti-twist ring</entry></row><row><entry> 34.4</entry><entry>Needle opening</entry></row><row><entry> 40</entry><entry>Pressure sink</entry></row><row><entry> 90</entry><entry>Fasteners</entry></row><row><entry> 91</entry><entry>Workpiece</entry></row><row><entry>100</entry><entry>Trip-ready state of the tool</entry></row><row><entry>101</entry><entry>Secured state of the tool</entry></row><row><entry>230</entry><entry>Connect to an energy source</entry></row><row><entry>600</entry><entry>Idle state of the trigger element</entry></row><row><entry>601</entry><entry>Pressed state of the trigger element</entry></row><row><entry>610</entry><entry>Actuate the trigger element from the idle state to</entry></row><row><entry /><entry>the pressed state</entry></row><row><entry>620</entry><entry>Actuate the trigger element from the pressed state</entry></row><row><entry /><entry>to the idle state</entry></row><row><entry>700</entry><entry>Non-actuated state of the workpiece contact element</entry></row><row><entry>701</entry><entry>Actuated state of the workpiece contact element</entry></row><row><entry>710</entry><entry>Actuate the workpiece contact element</entry></row><row><entry>720</entry><entry>Raise the workpiece contact element from the</entry></row><row><entry /><entry>workpiece</entry></row><row><entry>800</entry><entry>Inactive safety device</entry></row><row><entry>801</entry><entry>Active safety device</entry></row><row><entry>810</entry><entry>Activate the safety device</entry></row><row><entry>820</entry><entry>Automatic elapsing of the predetermined time</entry></row><row><entry>A1</entry><entry>First surface content</entry></row><row><entry>A2</entry><entry>Second surface content</entry></row><row><entry namest="1" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>